Failed to Start the X server (your graphical interface)

Problems with the X Server Crashing and Non-Root Users

If you are having trouble with the X server crashing when anyone logs in, you may have a full file system (or, a lack of available hard drive space).

To verify that this is the problem you are experiencing, run the following command:

[oracle@localhost ~]$ df -h

The df command should help you diagnose which partition is full. For additional information about df and an explanation of the options available (such as the -h option used in this example), refer to the df man page by typing man df at a shell prompt.

A key indicator is 100% full or a percentage above 90% or 95% on a partition. The /home/ and /tmp/ partitions can sometimes fill up quickly with user files. You can make some room on that partition by removing old files. After you free up some disk space, try running X as the user that was unsuccessful before.

OR

This problem may be resolved in this way:

1. When the message about viewing the X server output came, I pressed Ctrl Alt F2
2. Now on the new shell I ran command sudo Xorg -configure
3. Then I copied /home/oobe/xorg.conf.new to /etc/X11/xorg.conf
sudo cp /home/oobe/xorg.conf.new /etc/X11/xorg.conf
4. At last I started X using command startx.

Access Django app from other computers

This is very very simple

change in setting.py

ALLOWED_HOSTS = ['*']

python manage.py runserver 0.0.0.0:8000 

open linux terminal

sudo ifconfig

Get inet ipv4 address Run on other same local network PC

If you find following error

Using the URLconf defined in mysite.urls, Django tried these URL patterns, in this order: 

1. polls/ [name='index'] 

2. admin/ 

The current path, polls/, didn’t match any of these. Then

replace path(' ', views.index, name='index') with path('', views.index, name='index') in your polls/urls.py and check the result.

Installation and setup of SAMBA and TkSmb in RedHat Linux 5

SAMBA is an open source software suite that provides seamless file and print services to SMB/CIFS clients. It is available for Linux, Solaris, SunOS, HP-UX, ULTRIX, DEC OSF/1, Digital UNIX, Dynix (Sequent), IRIX (SGI), SCO Open Server, DG-UX, UNIXWARE, AIX, BSDI, NetBSD, NEXTSTEP, A/UX, etc. For a detailed introduction see this article. Linux machines using SAMBA are seen by NT as part of a NT Domain and can share printers and directories with Windows (95/98/NT) machines. This tutorial will cover the basics of installing and setting up SAMBA, and also TkSmb, a graphical tool to manage shares between Linux and NT.

Read more...
 

ORA-01017 Invalid username/password logon denied

In Oracle 11g a new parameter called SEC_CASE_SENSITIVE_LOGON which is defaults to TRUE for case sensitive passwords. My SCOTT password was "tiger" is small case and Forms 10g was taking it as "TIGER" on runtime.

Solution 1:

- Connect as sys and change the parameter to false.

      alter system set SEC_CASE_SENSITIVE_LOGON = FALSE; 

ORA-01658: unable to create INITIAL extent for segment in tablespace SYSTEM

Import terminated successfully with warnings.

ALTER DATABASE DATAFILE 'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF' RESIZE 3000M;

Or by adding a second datafile to the tablespace:

ALTER TABLESPACE SYSTEM

ADD DATAFILE 'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF'

SIZE 1000M;

Or just allow the datafile to auto extend:

ALTER DATABASE

DATAFILE 'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF'

AUTOEXTEND ON

MAXSIZE UNLIMITED;

ORA-00845: MEMORY_TARGET not supported on this system (During Starting Instance )

APPLIES TO:

Oracle Database - Enterprise Edition - Version 11.1.0.6 and later
Oracle Database - Standard Edition - Version 11.2.0.1 to 11.2.0.1 [Release 11.2]
Linux x86
Linux x86-64
***Checked for relevance on 30-Sep-2014***

SYMPTOMS

During the startup of the database instance the following error is raised:

SQL> connect sys as sysdba
Enter password: *****
Connected to an idle instance.

SQL> STARTUP NOMOUNT
ORA-00845: MEMORY_TARGET not supported on this system

The instance alert file shows:

Starting ORACLE instance (normal)
WARNING: You are trying to use the MEMORY_TARGET feature.
This feature requires the /dev/shm file system to be mounted for at Least <size> bytes.The /dev/shm is either not mounted or is mounted with available space less than this size.
Please fix this so that MEMORY_TARGET can work as expected. Current available is <size> and used is <size> bytes.memory_target needs larger /dev/shm

Also error messages like ORA-4031 may be reported and no new connections can be established to the database.

CHANGES

The Automatic Memory Management (AMM) has been implemented by setting parameters like MEMORY_TARGET and/or MEMORY_MAX_TARGET.

CAUSE

The new Automatic Memory Management functionality uses /dev/shm on Linux for SGA and PGA management. The errors occur if either MEMORY_TARGET or MEMORY_MAX_TARGET is configured larger than the configured /dev/shm size, or if /dev/shm is mounted incorrectly.

SOLUTION

Please confirm that ORACLE_HOME is set correctly. This error sometimes happens when it is not set correctly.

Make sure that the /dev/shm size is configured large enough, like in:

# mount -t tmpfs shmfs -o size=7g /dev/shm

In this case, the size of the shared memory device is configured to be 7GB.

In order to make the same change persistent across system reboots, add an entry for this to the /etc/fstab mount table, as in:

shmfs /dev/shm tmpfs size=7g 0

Note:

You should check with your System Administrator what the "best" size for /dev/shm is, based on what has been reported in the alert file. 

Also, many best practices now suggest disabling AMM especially in Exa* Engineered boxes that have larger memory capability and can use Huge / Large pages.
This is because AMM and Huge / Large pages are mutually exclusive and overall performance will be better using Huge pages

Make sure that the df output shows the correct /dev/shm configuration when using Oracle on the system:

$ df -k
Filesystem 1K-blocks Used Available Use% Mounted on
...
shmfs 6291456 832356 5459100 14% /dev/shm

This document is taken from Oracle Support Doc ID 465048.1 

ORA-01034: ORACLE not available or ORA-27101: shared memory realm does not exist

Open command prompt and execute the below commands:

set oracle_sid=DATABASE NAME

sqlplus /nolog

conn sys/sys as sysdba

shutdown abort

startup